1. Field of the Invention
This invention relates to novel strain resistant nylon carpets and to a novel process for providing such carpets. As used herein, the term "nylon carpet" means carpet in which the yarn used in making the pile fabric thereof consists essentially of nylon yarn, the term "yarn" means a continuous strand of fibers and the term "fibers" includes fibers of extreme or indefinite length (i.e. filaments) and fibers of short length (i.e., staple).
The term "stain resistant" when used herein with reference to carpet means carpet having the ability to resist staining when subjected to Food, Drug and Cosmetic Red Dye No. 40 (herein after referred to as Red Dye 40) under the conditions set forth in the Stain Resistance Test given hereinafter. Briefly, the test involves subjecting a test sample of carpet to two standard washing cycles in a conventional washing machine and then immersing the sample in a solution containing Red Dye No. 40. If the carpet is not visibly stained by the dye under the test conditions, the carpet is stain resistant within the meaning of the term as used herein. The purpose of the test is to identify carpets having durable and lasting resistance to staining normally caused by Red Dye 40.
Red Dye No. 40 is an acid dye having the following structure: ##STR1##
2. Description of the Prior Art
Nylon carpet is a popular floor covering for both residential and commercial applications. Such carpeting is relatively inexpensive and offers a desirable combination of qualities, such as aesthetics, comfort, safety, warmth and quietness. Also, it is available in a wide variety of attractive colors, patterns and textures. However, nylon carpet is permanently stained by most artificial colorants normally added to foods, beverages, medicines, cosmetic, etc., the most common of which is Red Dye No. 40.
It is a conventional practice to coat nylon carpet fibers with a fluorochemical to prevent wetting of the carpet surface and thus minimize contact between the carpet surface and foreign substance (e.g. soil). However, such an approach offers very little protection to the carpet in instances where the foreign substance is a substance such as Red Dye 40 unless, of course, the substance is immediately removed from the carpet before it has a chance to stain the carpet. Surveys of the carpet replacement market show that more carpets are replaced due to staining than due to wear. Therefore, there is a need in the art to develop stain resistant nylon carpet having the ability to retain its original appearance for an extended period of time.